Sheet feed control means for rotary hectographic copying machines



R. BROWN SHEET FEED ccm'mor. MEANS FOR ROTARY March 11, 1958 2,826,141

HECTOGRAPHIC COPYING MACHINES Filed Feb. 26, 1954 INVENTOR ATT qRN s Unitfed States Patent SHEET FEED CONTROL MEANS FOR ROTARY HECTOGRAPHIC COPYING MACHINES Roland Brown, London, England, assignor to Block &

Anderson Limited, London, England Application February 26, 1954, Serial No. 412,891

Claims priority, application Great Britain March 2, 1953 Claims. (Cl. 101-1325) This invention relates to copying machines of the kind in which the sheet on which the copy is to be made is fed by means of a pair of feed rollers to the printing position in which the sheet passes between a drum carrying the hectographic master to be copied and a co-opcrating pressure roller, the feed rollers being driven from the rotation of the drum during the initial movement of the drum from its rest position and thereafter being entrained by the copy sheet as it is fed forward by the co-operating drum and pressure roller. An example of such a machine is to be found in British Patent 682,842. In such machines, the solvent used for moistening the copy sheet on its passage to the drum may conveniently be applied by way of the upper feed roller. Usually the drum is releasably located in its rest position by means of a spring-loaded arm carrying a roller or other cam follower adapted to engage in a dwell on a cam, the cam being mounted to rotate with the drum and the arm being pivoted to the stationary frame of the machine.

:Normally the machine is used to copy from a master of a length less than the periphery of the drum so that each rotation of the drum from rest position to rest position corresponds to a complete copying operation. Sometimes however it is necessary to take copies from amaster sheet of greater length than the periphery of the drum, so that the drum has to make more than one revolution to enable a copy to be made, and after each copying operation the drum has to be rotated in reverse to unwrap the master sheet so that a further copying. operation can be performed. During this reverse rotation there is no copy paper between the master and thepressure roller and it is desirable therefore that the pres-- sure between the roller and the drum should be released. It is alsodesirable that the drum locating device should be inoperative during the copying operation.

According to the present invention means are provided;

.Whereby after the first rotation of the drum, the drive tothe feed rollers can be interrupted automatically so that the feed rollers are driven only while the copy sheet is engaged exclusively by said feed rollers. If the drive of the feed rollers is derived from a cam follower co-opcrating with a cam rotating with the drum, the interruption of the drive may be effected by a latch member adapted to retain the follower in an extreme throw position so that it is not oscillated by the cam. The latch member may be spring loaded and normally retained in an inoperative position against the spring-loading but released by an operator-controlled lever when it is desired to take long copies. The same lever may also serve to control the drum locating arm to render the drum locating device inoperative.

Thus when the operatoncontrolled lever is set to theposition for long copies, the spring-loaded latch member is released and when the cam-follower from which the feed roller drive is derived reaches its extreme throw position, the latch member engages it to hold it stationany so that no further feed motion is imparted to the feed rollers.v When the long copy has been taken, the pressure of the pressure roller is released to enable the drum to be reversed to unwrap the master therefrom. The pressure control is linked to the latch so that the latter is tripped by the action of releasing the pressure. For this purpose, the pressure control lever may engage a stud or like projection on a link hinged to latch member, so that release of pressure causes the control lever to engage the stud to-move the link and thereby trip the latch. Movement of the pressure control lever in the opposite sense to apply pressure is independent of the link.

The arrangement for disabling the drum locating device is preferably such that the reverse rotation of the drum trips it, so that the drum is located again when it reaches its original starting position. On the next long copying operation, the drum locating device is again held out of operative position as soon as the drum has moved out of its rest position.

When the machine is set for normal operation a catch positioned by the operator-controlled lever is in a position to engage and hold the latch member in an inoperative position.

In order that the invention may be more readily understood and carried into effect, an embodiment will be described with reference to the accompanying drawing, which is a view looking at the inside of the left-hand side frame of a hectographic copying machine, and which shows in detail only those parts of the machine which are modifications of or additions to an existing machine constructed according to British Patent 682,842.

The left-hand side frame is indicated at 1. Journalled in the side frame are a printing drum 2 on which is secured a master sheet bearing in mirror script in hectographic ink the matter to be reproduced, and a co-operating pressure roller 3. The drum 2 is located in its rest position by means of a cam 4 secured for rotation with the drum 2 and provided with a dwell 5. A roller 7 carried by a locating arm 6 pivoted on the side frame 1 is urged by a spring 8 to bear against the edge of the cam 4 and by engagement in the dwell 5 releasably locates the drum 2 in its rest position. For the copying operation, the pressure roller 3 is urged again-st the drum 2, the pressure being adjustable in well-known manner by means of a lever 9 for instance, by mechanism similar to elements 4 to 21 inclusive in British Patent No. 604,565 in which the pressure of roller 4 on roller 1 is controlled.

In the position of the lever 9 as shown, the pressure is off, and pressures of progressively increasing magnitude are obtained by rocking the lever 9 counter-clock wise about its pivot 10. The lever 9 is held in its adjusted position by means of a rack quadrant 11 from which it can be released be depressing the knob 12. The movement of the lever 9 controls in well-known manner the position of a cam which controls the thrust of a spring arrangement 30 provided for urging the pressure roll-er 3 against the drum 2. The copy sheets on which the copies are to 'be obtained, :are fed singly to the printing couple 2, 3 by a pair of feed rollers 13, 14 the feed movement of which is derived from the rotation of the drum 2. For this purpose a cam 15 is associated with the drum so that a rocker 16 provided with a follower roller 17 is oscillated by the rotation of the drum. A spring 30 engages the arm 19 of the rocker 16 and holds the cam follower roller 17 in engagement with the cam 15. In the manner more fully described in British Pat- =ent No. 682,842 the movement of the dependent arm 18 :of the rocker 16 may be transmitted to a toothed sector .31 meshing with a toothed wheel 32 which is coupled with the drive for the feed rollers 13, 14 by way of a unidirectional coupling 34, so that the feed rollers are driven during movement of the sector in one direction, but not in the other. The copy sheets are moistened l atented Mar. 11, 1958- With witha solvent fontlieh'ectographic ink as they are fed to the printing couple. This-moisteningmay be effeoted in any convenient way, as for example by supplying the moistening solvent tothe upper feed roller.

In; :normal r-operation of the s machine theifeedz rollers 1 13'; 14 are-operative: duringneach rotation andzthe drama is releasablyslocated in 'itsrrestposition at the :end of each rotation.

To enable :'long copies. to'betaken from: master sheets which are longer-thaw the; periphery of the drum *2, the i mechanismswhich will now bedescribedare provided.

Pivoted at 21*to'the side. frame l'isa latch 20 the upper end '5 of which is 1 adapted to engage belowa pin 19d on therarm'w when the rocker 16 is in itsv extremethrow position determined by the cam 15. When the latchrZil engages *below: the pin 19a-ancl' supports the arm 19, the rocker-:lG-cannot follow-"thecamcontour and remains stationaryso that no further-feed. movement is: imparted to the .feed rollers'13,14. During normal? control levera 25:. in1 clockwise1 direction, therebysimultaneous'ly turning:thevassociated cam .26 in-the same direction: Thismovementof :the :cam26causes the: catch 22 to: turn. zcounterclockwise about its *pivot 23, .thereby releasing-the latchi- 20; Pnt'thesametime, the cam26 rocksthe arm. 6' to:lift the'roller-7 out-of the dwell in the locating-cam 4. Then,..wh'en-the copyinguoperation' is commenced, the rocker 16 is rocked and the feed rollers are operated during the first rotation of the drum 2. However, as soon as the rocker 16 reaches its maximum throw, .the latch 20 canengage below the pin 19a on the arm 19 of the-rocker 16 to hold the latter against further movement. continued .theuequisite number of times to complete the long. copying operation. At this stage, the long masterxis wrappedzround-the' drum 2 and it must beunwrapped before a further copying operation can be performed. The first step is to release thepressure by moving thepressure control lever 9 into the off position 'as'shown in the drawing.- Thismovement of the lever 9'7-is utilizedrto:withdraw-the latch 20. from .the rocker 16. Thisis achieved jbyaneans ofa link 27 attached to the lower" end of the latch; 20 andpr-ovided with'a pin 28' in the'pa th of movement of the lower end of the lever 9.

Ifthe lever-25-has1beerrrestored to the position shown in' the drawing, the-catch 22 :re-engages the latch 20 as shown and normal copyingcan take'place. If however Rotation of the drum can then bethe lever 25 has been left in the long position, then the catch 22 is maintained out of-engagement-with thelatch 20 and the cycle of operations for taking long copies can be repeated after restoring the lever 9 to the position appropriate to the desired pressure between pressure roller 3 and drum 2.

I claim:

1. In a copying machine a copy-printing drum; rollers 'for feeding sheets to said-drum, drive means for said rollers connected to be driven from said drum, and se-- lective.y operable means controlled 'by rotation of'said drum functioning after a predetermined rotation thereof to disconnect the feeding means drive fromsaid "drum :after the first revolution of said drum whereby after said first rotation of the drum the drive to said feed rollers is interrupted automaticalljgso that thefeed rollers are driven only while the copy sheet is engaged exclusively by the said feed rollers.

2. A machi'ne' as claimed in claim l and in "which the the drive connection between the" fee'd' rollers'and 'dr'iln'l" ineludesa cam rotating with the drum, and a cam follow enengagirig said cam and oscillated thereby, said follow er beingconnected to drive said rollers" by "its oscillatio'n; and in which adatch member is provided which' is adapted to retain said follower in 'an'extreme throw position foi" effectingthe interruption "of said "rollers drive. i

3. -A-machine according toclaim 2 and in which said latch-memberis movable from sa'id"follower-retaining' position toaminoperative position, a sprin'g'for engaging and loadingsaid 'latch member in inoperative position,

and a 'catch' normally'engaging saidlatch member and retaining it in inoperative position.

4-; Amachine according to claini3, and in which a pressureaoller is provided pressing'against' said drum,

means for controlling the pressure'between said pressure References Citedinthe' file ofthis patent UNITED .STATES PATENTS BIOdt'i; Dec-l2, 1944 Kiel; May 20, 1.952 

